This issue is being caused by an incompatibility between certain antivirus applications and the recent Windows Updates to Windows 7, 8.1 and 10. Sophos, Avast, and Avira have all been confirmed and are working with MS for solutions. I'm sure there are others, but those three are the ones I could locate info on. Most specifically Avira since that's what I use and they gave me the following response:
Hello, Our dev. dept. is in contact with Microsoft to find a solution for this issue. Please see this article which we've published some hours ago:
*https://www.avira.com/en/support-for-home-knowledgebase-detail/kbid/1976*I'm certain the temporary solution for whatever AV you may have is the same as what Avira has stated. Just uninstall the corresponding Windows Update as mentioned in the article, wait for your AV provider to release an updated version to install, then reinstall the Windows Update(s).